Sound reproducing system



March 27, 1951 w, KENE 2,546,278

SOUND REPRODUCING SYSTEM Filed Sept. 1, 1944 3 Sheets-Sheet 1 R@- W Skene \nV.,

March 27, 1951 R w, SKENE 2,546,278

SOUND REPRODUCING SYSTEM Filed Sept. 1, 1944 5 Sheets-Sheet 2 March 27, 1951 w, SKENE 2,546,278

SOUND REPRODUCING SYSTEM Filed Sept. 1, 1944 3 Sheets-Sheet 3 ken6 Patented Mar. 27, 1951 UNITED STATES PATENT OFFICE SOUND REPRODUCING SYSTEM Roy William Skene, Rouyn, Quebec, Canada Application September 1, 1944, Serial No. 552,271

3 Claims. 1

This invention relates to radio receiving and reproducing apparatus, and more particularly to electrical apparatus adapted to suitable control thereof when interposed in the electrical circuit between any radio receiver and radio reproducers of the special acoustical type known to the art as pillow speakers, or in the circuit between any electrical device the output current of which is in the form of electrical oscillations which have been modulated for sound reproduction, and the acoustic apparatus in which said modulated electrical impulses are converted into audible sound, whether the said electrical devices are remote from one another or in close proximity.

One object of my invention is to provide a suitable method of remote control for pillow speakers by means of which the person using same may switch it into, or out of the output circuit of a radio receiver at will without the necessity of going from the pillow speaker to the radio receiver, which may, or may not be in the same room or on the same floor.

A further object is to provide a separate control unit which may be placed on a table or chair beside a couch or hospital bed within easy reach of the person who is using a pillow speaker, thus affording the user individual control of the pillow speaker while remaining in a comfortable reclining position, for use in hospitals, apartments or homes where it is desirable that radio programmes may be enjoyed at will by some, with out causing any inconvenience to others.

Another object of my invention is to provide a separate portable control unit adapted to plug into any radio receiver or similar device, which includes suitable outlets for such use, thus extending its usefulness to more than one radio receiver.

Those which were not manufactured for this purpose may easily be modified by any person skilled in radio servicing.

Still another important object of my invention is to provide a suitable electrical circuit which may be built into radio receivers by the manufacturer for the control of pillow speakers remote from the receiver, and which may be used alone or in conjunction with a portable individual control unit, making it possible to use the receiver in one room and a pillow speaker wired to another room, each separately or at the same time as ma be desired.

An equally important object is to provide a control unit which may be used for the purpose of transferring telephone calls from one telephone to an extension telephone on the same line or in the same building.

With the above noted and other objects in view which may appear as the description proceeds the invention resides in the novel construction, combination and arrangement of co-operating parts as hereinafter more specifically set forth, claimed and shown in the accompanying drawings forming part of this application, and in which:

Figure 1 is a circuit diagram of the apparatus.

Figure 2 is a circuit diagram of a modified form of the apparatus.

Figure 3 is a modified circuit diagram of the apparatus as used in a push-pull output circuit and using transformer coupling to pillow speaker.

Figure 4 is a partial circuit diagram as above but using condenser coupling to pillow speaker as an alternative.

Figure 5 is a circuit diagram of the apparatus, and similar to Figure 1, except that condenser coupling to pillow speaker is used in place of transformer.

Figure 6 is a modified circuit diagram of the apparatus similar to Figure 2, as used in a pushpull output circuit and using transformer coupling to pillow speaker.

Figure 7 is a partial circuit diagram as above, but using condenser couplin to pillow speaker as alternative to transformer coupling.

Figure 8 is a circuit diagram of the apparatus similar to Figure 2, except that condenser coupling to pillow speaker is used in place of transformer.

i Referring to the drawings in greater detail circuit connection to any radio receiver may be made by providing suitable terminals 8, in the output circuit between the last audio tube 9 and the output transformer i 9, so that the modulated output current is routed through the control switches H and I2 before passing to either the radio receiver speaker M, or the pillow speaker 1, Having thus channeled the output current through the control switches, selective control is accomplished by operating switches H and i2 to direct the output current from the radio receiver fthrough the radio receiver speaker it alone, or through the pillow speaker I alone, or through both together as desired. In the circuit shown in Fig. 1 the switch II is a doublepole-double-throw switch and consists of movable contacts Ha connected as shown to the output circuit of the radio receiver and stationary contacts ill) and lie respectively connected to the circuits of the speakers It and l. The switch I 2 is a double-pole-single-throw switch and consists of movable contacts l2a connected as shown to the circuit of speaker l4, and stationary contacts 12b connected to the circuit of the speaker I. When the movable contacts Ila of switch H are engaged with stationary contacts ilb and switch I2 is open the speaker M will operate alone. With the contacts I la engaged with contacts Ho and switch 12 open the speaker i will operate alone. When contacts Ha of switch II are engaged with either the contacts Hb or He and with switch l2 closed, the speakers 14 and I will operate in unison. Switch I I is of the type known in the art as a shorting switch, in order to prevent injury to the tubes of the radio receiver due to voltage surge. An audio transformer l3 may be included in the circuit of speaker I to match impedance of the pillow speaker if not included in the latter. A variable resistance volume control I5 is also included in the circuit of speaker I to control the sound level of the speaker I only. In addition an elec trostatic fixed condenser l6 may optionally be connected across the secondary terminals of audio transformer 13, as required. The switches employed may be of the toggle type or any other type which will accomplish the same result.

Referring to Figure 2, the control switches l1 and 26 are preferably single-pole-triple-throw switches ganged on the same shaft to operate in unison. The switches I! and 24 have a movable contact 11a and 24a connected as shown to the output circuit of a radio receiver. The switches are connected together so the movable contacts move in unison to selectively engage. stationary contacts [1b, 110, Nd and 24b, 24c, 2401. The contacts Ill) and Ilc of switch I? are dead and contact lid is connected to the circuit of speaker 14. The contact 2419 of switch 24 is connected to the circuit of speaker 14 and contacts 240 and 2401 are connected to the circuit of speaker I. When the switches l1 and 24 are in the position shown in Fig. 2 the circuit of speaker M will be closed and the circuit of speaker I open. With the switches engaged with contacts He and 240 the circuit of speaker I will be closed and the circuit of speaker l4 open. When the switches are engaged with contacts Nd and 24d the circuits of speakers l4 and 1 will both be closed and the speakers will operate in unison.

Referring to Figure 3, an arrangement similar to that shown in Figure 1, is diagrammatically represented, showing the adaptation to a receiver having push-pull output tubes I9, and transformer 20, connection to the receiver being made in this case in the transformer secondary leads at 2|.

In Figure 4, the use of condenser coupling to pillow speaker is shown as an alternative method, condenser 22, in series and resistor 23, in shunt replacing the audio transformer I 3, in a circuit otherwise the same as Figure 3.

In Figure 5, the circuit is the same as Figure 1, except condenser coupling to pillow speaker is used to replace audio transformer l3.

Figures 6 and 7 illustrate diagrammatically the same alternative speaker couplings as described above in Figures 3 and 4, but using single control switch ll, as shown in Figure 2. Figure 8 again snows condenser coupled pillow speaker with single control switch and single output tubeas previously shown in Figure 2, except the coupling condenser 22, and resistor 23, replace the audio transformer 13. By using condenser coupling savings in cost and weight and greater simplicity may be obtained.

It is believed that the construction and advantages of the structure shown may be apparent from the foregoing paragraphs taken in conjunction with the accompanying drawings without further detailed description.

While the preferred embodiment of the invention has been disclosed it is understood that minor changes in the details of construction, combination and arrangement of co-operating parts may be resorted to within the scope of what is claimed without departing from the spirit of the invention.

Having thus given a true and complete de-.

scription of my invention, what I claim is:

1. In combination a radio receiver, a pair of speaker circuits, a double-pole-double-throw switch for selectively connecting the speaker circuits to the output circuit of the radio receiver having its movable contacts connected to the output circuit of the radio receiver and its stationary contacts respectively connected to the speaker circuits, and a double-pole-single-throw switch having its movable contacts connected to one of the speaker circuits and its stationary contacts connected to the other speaker circuit, said double-pole-single-throw switch, when closed, connecting the speaker circuits to operate in unison when said double-pole-double-throw switch is closed on either side.

2. The combination as described in claim 1 including a variable resistance in the circuit of one of the speakers.

3. The combination as described in claim 2 including an audio transformer in the circuit of one of the speakers.

ROY WILLIAM SKENE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,724,191 Goldsmith Aug. 13, 1929 1,833,085 Macnabb Nov. 24, 1931 1,864,615 Quinby June 28, 1932 1,866,687 Wheeler July 12, 1932 1,922,415 Banks Aug. 15, 1933 2,110,358 Dreisbach Mar. 8, 1938 2,140,032 Sears Dec. 13, 1938 2,319,527 Zavattaro May 18, 1943 2,333,617 Smith Nov. 2, 1943 

